Tiny particles make a big difference in controlling internal bleeding

Nanoparticles (green) help form clots in an injured liver, in this color-enhanced microscope image(Credit: Erin Lavik, Ph.D. )

While there are already ways of controlling bleeding from external wounds, surgery is typically the only option when it comes to stopping internal bleeding. That could be about to change, however, thanks to research being conducted at the University of Maryland, Baltimore County (UMBC). Scientists there are developing injectable nanoparticles, that speed the clotting of blood at internal wound sites.

Each particle contains a molecule that binds with a certain glycoprotein, which is found only on activated platelets.

This means that when administered intravenously (such as would be done at an accident site or on a battlefield), the nanoparticles travel through the bloodstream until they get to a wound site where platelets are already at work, causing the blood to clot. By binding with those platelets, the particles help fill the gaps between them, causing that clotting to occur more quickly.

In lab tests on rodents, the technology has reduced bleeding time by 50 percent. That said, rodents aren't humans. To that end, the researchers have experimented with introducing the nanoparticles into pig blood, which is more similar to that of people.

Initially, it was found that the particles triggered an immune response in the pig blood. This was addressed by using neutrally-charged nanoparticles, although making that change caused the particles to aggregate with one another, before even being injected. This problem was in turn addressed by adding a slippery polymer to the nanoparticle storage solution, to keep the particles from joining together.

Next up, the scientists plan to see if the nanoparticles trigger an immune response in human blood. If everything works out, it is hoped that the technology could see practical use within five to ten years.

The research is being led by Prof. Erin B. Lavik, and was presented today in Philadelphia, at the 252nd National Meeting & Exposition of the American Chemical Society.